“That investigation culminated in a series of search warrants this morning.”

Eight of the 21 residences searched are in Waterloo Region, including Kitchener homes on Queen’s Boulevard, Lorne Avenue and Vanier Drive.

On Lorne Avenue, in Kitchener’s Southdale neighbourhood, police spent many hours at the scene due to difficulty clearing a path to remove goods from the home. Neighbours call the resident a hoarder, though a friendly person.

"He seems like a nice gentleman," said neighbour Frank Calder.

"The only thing is that there's a lot of junk in the backyard. I don't know why the city never got after him or the people who lived next door never got after him."

The house was in fact so packed that bylaw officers and fire officials were called to the scene to assess its safety.

Thaler says more information on the arrests, seizures and charges is not yet available.

“Several dozen people are under arrest. Further details will be provided as the day rolls on,” he said.

Drugs, guns, cash and explosives were seized from the various residences and more than 12 people were taken into custody in Waterloo Region alone, Thaler said.

With so many residences in Waterloo Region to be hit at the same time, just after 6 a.m., officers were brought in from other jurisdictions to assist.

“We required resources from partners in Toronto, Halton, Hamilton, Guelph Police Service, Kingston Police Service and the OPP in Waterloo,” said Thaler.

Police say the investigation focused on a network of production, distribution and sale of illicit drugs.

More information is expected to be revealed at a Thursday afternoon police press conference.